Flashcards in Chapter 42: Circulation and Gas Exchange Deck (14)
What is one of the evolutionary adaptations of animals?
Gas exchange with the environment through specialized surfaces that are extensively branched or folded.
An arrangement that protects delicate tissues from abrasion or dehydration and allows for streamlined body contours
Why are the tissues of the surfaces branched and folded?
To maximize surface area for gas exchange
What does it mean for an animal to be endothermic?
They are warmed mostly by heat generated by metabolism
What does it mean for an animal to be ectothermic?
They gain most of their hear from external sources
___________ (endotherms/ectotherms) can maintain stable body temperature even in the face of if large fluctuations in the environmental temperature.
What does the circulatory system do?
Moves fluid between each cell's immediate surroundings and body tissues where exchange with the environment occurs
What happens in an open circulatory system?
Hemolymph (interstitial fluid that bathes body cells) is not confined to the blood vessels.
- mostly sedentary animals have this because of low flow rates
- insects also have this
What happens in a closed circulatory system?
Hemolymph (interstitial fluid that bathes body cells) is within the blood vessels.
- blood flows in a continuous circuit through the body under pressure generated by the heart
- vertebrates, earthworms, annelids, squid, octopuses etc have this
Explain how the heart works using the concepts of pulmonary circulation and systemic circulation.
1. Blood (from body) enters right atrium
2. Blood enters right ventricle
3. Blood is pumped from right ventricle to lungs
4. Blood (from lungs) enters left atrium
5. Blood enters left ventricle
6. Blood is pumped from left ventricle to body
What is single circulation?
When the blood passes through the heart once in each complete circuit through the body
- occurs in fishes, rays and sharks
What is double circulation?
When the blood passes through the heart twice in each complete circuit through the body
- occurs in mammals, amphibians and birds
What type of blood circuit do amphibians have?
Pulmocutaneous circuit (double)
- blood travels to skin and lungs